Nozzle



July 3, 1945. J, A; HEANY 2,379,432

NOZZLE Filed A ril 21, 1942 INVENTOR' Jay/v ALAE/V Asww A'ITQRNEYS Patented July 3, 1945 Nozziiir I John Allen Heany, New Haven, Conn., assignor to Heany Industrial Ceramic Corporation, Roch ester, N. Y., a corporation of New York Application April 21, 1942, Serial No. 439,814

nection with sand-carrying fluids such as air sand blast nozzles or oil well choke nozzles.

Among the objects of the invention is the provision of a nozzle resistant to abrasionbetween the nozzle orifice and tip,-and giving stream concentration without increasing wear at the nozzle tip. The invention also contemplates as obiects a nozzle impairing high velocity to the stream within the nozzle without increasing nozzle wear and impartingv acceleration to the stream beyond the nozzle tip; a nozzle of simple design and involving relatively low manufacturing costs; and a nozzle operable at a relatively low cost per work hour. v

Other objects will appearon consideration of the following specification and accompanying drawing, in which:

' Fig. 1 is a sectional view of a nozzle embodying my invention; and

Fig. 2 is a modification of the nozzle of Fig. 1.

The usual sand blast nozzle consists of a metal tube having a cylindrical bore terminating at the rear end in a flared orifice, a cone of about 45 being common. The metal varies with the use, pressure, and bore, extending from iron to various hard steels and tungsten or boron carbides. In any case, however, the bore except for the orifice is cylindrical and hence of uniform diameter.

In the operation of a nozzle of this type, after passing through the bore, the air column ex-- pands at the tip, causing wear, the material being removed to an angle of about 13 from the nozzle axis. The wear begins at the tip and continues backwardly to the inlet orifice to produce the conical duct. When the top of the 3 cone reaches the orifice and begins to enlarge the same, the efficiency of the nozzle drops rapidly and the nozzle must be discarded. This efiiciency drop follows from the increased fiow of air since for an inlet enlargement, say from to 1 s. at 60 lbs. pressure there is an increase in air flow of 151 to 205 cubic feet per minute.

I have discovered that by shaping the nozzle duct as a frustrum of a cone with the apex'at the tip, erosion of the nozzle material is greatly reduced. A nozzle of this type is illustrated in Fig. 1 comprising the casing 20, the attaching flange 2| and the conical duct 22. It is noted that the cone slope is continuous from inlet 23 to outlet 24. The angle of slope with reference to the nozzle axis may Vary between limits, the essential requirement being a decrease in diameter from inlet to outlet. A range of 1 to 6 has been found to give superior results, with 4 46" or a slope of approximately one inch in one foot showing optimum values.

Since the material wear is greatly reduced a wide variety of materials may be employed successfully in these nozzles, including cast iron,

' steel, tungsten carbide, boron carbide and many ceramics.

While the principle of operation of my nozzle isnot fully understood, the improved efliciency seems to be due in part to the prevention of expansion of air flow within the nozzle, thereby preventing the eroding action of the abrasiveson' the interior nozzle surface. This action may be explained by the fact that the air stream in the I nozzle is given a convergent flow which changes to a zero angle parallel to the nozzle axis at the tip. At this angle there is minimum tendency for sand wear on the tip.

As an example of p the resistance to wear of my improved nozzle, reference is made to the following test:

Length of bore 2%" Diameter of bore at outlet Diameter of bore at inlet 1%" Taper w 1" to 1 Abrasive Steel grit Air pressurelbs. Life 46 hours Diameter of bore at outlet: At the start 0.375" At the end of 20 hours 0.493" At the end of 30 hours 0.546" At the end of 46 hours 0.585"

This compares with a life of not over five hours for an, ordinary straight bore nozzle of the same minimum bore, length and material and utilizing the same abrasive.

In Fig. 2 is a modification including the casing 30, attaching flange 3| and duct 32. In this 1 form of the invention the duct wall, instead of forming a cone frustrum, is curved convexly inwardlyfrom inlet 33 to outlet 34, thus producing a gradual straightening of the sand blast stream I adjacent the outlet.

Either form of the invention may be utilized, dependent on the nozzle material, air pressure,

sand and purposes for which the nozzle is emvergence of the orifice cone is relatively greater than that of the nozzle cone.

Other modifications of the invention may also be used, the essential feature being the diminution in the duct diameter from inlet to outlet, as comprehended within the claims hereto appended.

I claim as my invention:

1. A nozzle forsand blasts,oil*chokes,:and the like comprising a tube having inlet and outet ends, the duct of the tube decreasing in size from the inlet to the outlet, the rate of size de-= crement of outlet relative to inlet being approximately two inches per foot.

2. A nozzle for said blasts, oil chokes and the like comprising a tube having inlet and outlet ends, the tube duct having the form of a cone frustrum with the large end at the inlet, the angle of convergence lying between 7 and 12.

3. A nozzle for sand blasts, oil chokes and the like comprising a, tube having inlet and outlet ends, the tube duct having a. straight taper convergingfrom inlet to-outlet, the'angle of conevergen'ce being'approximateb 9 32".

JOHN- ALLEN HEANY. 

